A frequency response characteristic of an electro-acoustic transducer needs to be known in some applications using audio enhancement techniques, such as binaural rendering and noise compensation (or cancellation). As used herein, an electro-acoustic transducer may comprise, for example, a headphone, a microphone, a speaker, and any other device which may transform electrical signals to acoustic signals. Furthermore, the frequency response characteristic may include, for example, a headphone to eardrum transfer function, a microphone to eardrum transfer function, a transmission loss of a headphone, a transmission loss of a microphone and the like.
In the application of noise compensation, for example, an appropriate gain for an audio signal played by a headphone is calculated to compensate an environmental noise signal in an ambient environment external to the audio signal. It should be noted that in the application of noise compensation, in order to calculate the gain, the frequency response characteristics of the headphone and a microphone associated with the headphone are usually measured to estimate the perceived audio and environmental noise signals. As used herein, a microphone associated with a headphone refers to a microphone, which may be inserted into or located near a headphone, which may record an environmental noise signal which may influence the perception of an audio signal played by the headphone. The measurement is often performed by an acoustic engineer using a professional measurement device. However, this approach may be costly and time consuming.